File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

AIF file extension

Audio Interchange File Format

Audio Files

ASF file extension

Advanced Systems Format File

Video Files

DB file extension

Database File

Database Files

DNG file extension

Digital Negative Image File

Camera Raw Files

HTM file extension

Hypertext Markup Language File

Web Files

LNK file extension

Windows File Shortcut

System Files

LUA file extension

Lua Source File

Developer Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SDF file extension

Standard Data File

Data Files

SH file extension

Bash Shell Script

Developer Files

TIF file extension

Tagged Image File

Raster Image Files

WSF file extension

Windows Script File

Executable Files

3G2 file extension

3GPP2 Multimedia File

Video Files